Background and Objective: Organizational citizenship behavior (OCB) is referred to as the voluntarily activities that are not included as duties in the job description or the formal system of rewards. Development of OCB can have a great impact on human resources performance and organization’s achievements. Similar with many other organizational variables, OCB as well is dependent on contextual factors. In this study, we explore the possible relationship between the Islamic ethics of business (IEB) and OCB among the health staff. Methods: A sample of 260 individuals was randomly selected from the health staff of Zabol University of Medical Sciences. OCB and IEB were assessed by Inventory of Oregon and Joseph’s standard seven-tem questionnaire, respectively, after ensuring their validity and reliability. The relationship between variables was examined by Pearson’s correlation test. Findings: Correlation analysis identified IEB as a significant predictor of OCB (r = 0.31, P < 0.05). In addition, significant correlations were identified between IEB and different dimensions of OCB, including social customs (r = 0.24, P < 0.05), altruism (r = 0.25, P < 0.05), Job awareness (r = 0.38, P < 0.01), individual mutual coordination (r = 0.21, P < 0.05), protection of organizational resources (r = 0.192, P < 0.05), chivalry (r = 0.18, P < 0.05), courtesy (r = 0.19, P < 0.05). Conclusions: Given the context-dependent nature of OCB, the health organizations in the Islamic countries can improve the OCB in their employees by promoting IEB among them.